Method for surfacing glass



April 6, 1965 E. L. WALTERS METHOD FOR SURFACING GLASS Original Filed Nov. 30. 1960 2 Sheets-Sheet l ATTORNEYS April 1965 E. WALTERS 3,176,441

METHOD FOR SURFACING GLASS Original Filed Nov. 3.0, 1960 2 Sheets-Sheet 2 10'] 104 INVENTOR.

A TTORN E YS t the polishing felts. cular pads of fairly restricted diameter so that the slurry United States Patent 3,176,441 METHOD FOR SURFACING GLASS Emmett L. Walters, Toledo, (thin, assignor to Libbey- Owens-Ford Glass Company, Toledo, ()hio, a corporation of Ohio Original application Nov. 30, 1960, Ser. No. 72,778, now Patent No. 3,107,458, dated Oct. 22, 1963. Divided and this application June 26, 1963, Ser. No. 297,480

5 Claims. (Cl. 51-4283) This invention relates broadly to the surfacing of glass and, more particularly, to an improved method which is for simultaneously polishing both surfaces of a continuous glass ribbon or sheet, moving along a definite path.

This application is a division of application Serial No. 72,778, filed November 30, 1960, now Patent No. 3,107,- 458, dated October 22, 1963.

i It has been known that a continuous glass ribbon may be ground and/or polished simultaneously on both sur faces as the ribbon moves along a definite path. This operation has been normally referred to in the prior art as either twin grinding or twin polishing. In the prior 'art, twin grinding was usually accomplished by a series of opposed circular grinding runners rotatable about a centrally disposed runner axis on each side of the glass ribbon. Likewise, the conventional twin polishing devices of the prior art employed a plurality of circular polishing pads freely rotatable about their individual axes, with said plurality of pads being supported on each side of the glassribbon from a common frame that was itself rotated about an axis perpendicular to the plane of the glass.

It has been further known, as shown and described in US. Patents Nos. 1,962,766 and 1,962,767, issued to J. P.

Crowley et al. on June 12, 1934, to surface (i.e. grind or polish) the opposed surfaces of a glass sheet moving along a definite path by a special type of oscillating motion of the surfacing unit, wherein the unit includes upper and lower generally rectangular surfacing runners extending substantially the full width of the sheet.

The particular motion of the surfacing tools, typified by' the above-cited patents, is most aptly defined as a curvilinear translation with respect to the glass. This curvilinear translation is itself most particularly characterized by the fact that the path of each point on the tool describes a circle, which circle is of equal diameter to the circles described by all other points on the same tool.

According to the prior art in which rotating circular tools or runners were employed, and particularly during the grinding process, the distribution of the grinding slurry to bring the slurry into proper position between a grinding runner and the glass was normally accomplished by inscribiug a series of radially spiralling grooves across the runner face. In this case, the slurry would be introduced through an opening at the center of the rotating runner and by centrifugal force would be carried along the outwardly spiralling channels so that the slurry would be distributed uniformly across the glass sheet.

" In the'case of polishing, the slurry was deposited directly upon the glass and was carried by the glass underneath Also, these polishing felts were ciror polishing rouge actually had to travel only a slight distance underneath the circular pad to reach the pad center and thereby insure uniform distribution of the polishing slurry underneath the pad.

However, with the advent of present polishing procedures, wherein rather large rectangular runners are used to surface the glass, a serious problem has arisen in connection with the proper slurry distribution underneath the entire glass contacting area of the surfacing tool. This problem is magnified in the case of the rectangular shaped polishing runners following a path characterized by a "ice curvilinear translation because it has been found that the pads or felts of the polishing runners must be pressed onto the glass surface by some external pressure in order to secure the best polishing action. Thus, it could be said, in the case of these rectangular polishing runners, that the glass sheet is actually pinched between opposed surfacing runners, This being the case, external feeding such as was common heretofore in the case of the circular polishing runners of the prior art has proven unsatisfactory. With the polishing runner positively pressed against the glass surface, this pressure prevents the glass sheet from carrying polishing slurry, or rouge deposited on its surface, underneath the full extent of the runner.

Efficient polishing depends to a large extent upon the uniformity of distribution of the polishing slurry over all areas of the glass to be polished. If the slurry distribution should be uneven, then the polishing action of polishing tools will be uneven and the resulting glass finish will be characterized by areas of high polish and areas of inferior polish.

In essence it has been found to be critical that the felt pads carried by the rectangular polishing runners be impregnated or saturated with the polishing medium. This impregnation of the felt is accomplished to a reasonable depth to insure that the glass engaging portions of the felts are saturated with a fluid polishing medium. This is essential not only to insure uniform polishing of the glass but also to prevent the frictional force from excessively heating either the pad or the glass, which heat would impair the polishing efiiciency or, under some conditions, could cause the glass to break. During polishing the felt tends to dry out due to the frictional heat so that a saturation or impregnation of the pad is desirable as aforediscussed. Thus, to an extent, the impregnation of the pad by a fluid medium is necessary for its cooling elfect along with its use for polishing.

It is, therefore, an object of the present invention to provide an improved method for simultaneously polishing both surfaces of a continuous glass ribbon or sheet.

Another object of the invention is the provision of a particularly novel method for insuring a positive and uniform distribution of a polishing slurry or fluid medium to all parts of a rectangular polishing tool pressed into contact with a glass surface in order to obtain a uniform polishing of all areas of the glass surface.

It is a further object of the invention to provide a novel and highly efiicient surfacing or polishing runner which includes a plurality of individually movable sections and means for periodically feeding a fluid polishing medium interiorly of at least one of said sections, and substantially simultaneously with said feeding, disengaging said section or sections being fed from the glass surface whereby said fluid polishing medium comes into contact with that portion of the glass surface immediately adjacent any disengaged runner section.

Other objects and advantages of the invention will become more apparent during the course of the following description when taken in connection with the accompanying drawings.

In the drawings wherein like numerals are employed to designate like parts throughout the same:

FIG. 1 is a diagrammatic front elevational view partly in section taken along a line transversely of the path of the glass illustrating a polishing apparatus of the rectangular type;

FIG. 2 is a side elevation showing the polishing position of the surfacing runners;

FIG. 3 is a schematic side elevation partly in section showing a detailed view of an upper polishing runner in accordance with the invention;

FIGJ4 is a broken vertical sectional view taken along lines 44 of FIG. 3;

In lower surfacing apparatus FIG. is a fragmentarycross-sectional viewgsimilar, I to FIG. 3, of a modificationof the present invention; and

FIG. 6 is a fragmentary, schematic elevational View" 1 partly in section. showing a lower polishing runner in accordance with the inventions Turning now to FIGS. 1 and 2, there is shown'a glass ribbonor sheet .10 being conveyed along in the direction 'of arrow 11 ('FIGS. 2 and'3) by suitable drive rolls' 13 and 14. The glass ribbon 10. is carried through a plurality ofxsim ilar' polishing stations A and B (FIG.- 2). Only one of these stations, namelystation A, is shown: in detail (FIG. '1) and inasmuch as stations'A and B (FIG; 2) are for all intents and purposes structurally equivalent, there being only a difierence in the phasing v of the motionof the surfacing toolsem'ployed in these stations, it is believed that a description-of station-A, (FIG. 1). willfsuflice as a description for both stations 7 VA and B. It should also be remembered that stations A and B constitute one, surfacing unit (FIG. 2) and tha t any desired number of thes'e units may belocated along the path of ribbon 10.5,

' Station A includes anju'p'per surface polishing apparatus or tool 15 and a lower rsurface' poli'shing apparatus The upper surfa i 'g apparatus 15" includes a rectangular polishing platen or runner indicatedfgenerally at 17' devices 41 and 42 are ide nticalg An L'-shaped arm 43 is pivoted at a shaft 44." This arm 43 has a toothed projection 45 on we end engaging complementary, teeth 46 on the casing 25. The'plunger 47 of the device 42 is con- Lnected to the other" end of arni 43 and carries a piston head 48 that is held'within a cylindrical hydraulic cylindcr 49. t i

This cylinder is whatrnight be commonly referred to' as having a double acting'pistonh The cylinder 49 in the embodiment shown is connected by-meansof suitable leads 50 and 51 to a source of vacuum and/ or pressure j inorder to raise or lower plunger-47 as desired. There- (see also FIGS. 4 and 5); This platen'1 7-has a felt 17 in bearings 20a and; also snitablyattachedito a'shaft 21 Each shaft 21 is connected by aworm gearin'gsystem 22.to' further shafts 23 which are themselves con-r nectedtO the drive shafts of motor 24and-vro tated thereby in the desired manner. Thus-,;theupper platen 17 will; follow a closed path, namely,,a curvilinear translatiomias the driving. force is imparted thereto bythe motor 24,; 'through the linkage 20;.21, 22 and 23 aforedescribedj" Shaft 21 is maintained vertically aligned by a casingI25. and ,while shaft 2-1is freely rotatablelwithin casing 25 working face 18 and the platen is driven inits curvilinear j translation by eccentric drive mechanisms 19; on'e" se cured adjacent each'end of platen 17.v Each" mechanism fore, asthe plunger on piston 47 is optionally driven, for examplgzdownwardly in the direction of v arrow 52 .by

inserting pressureinto cylinder 49 from lead 50 and simultaneously bleeding pressure out throughlead 51, casing 10. and therefore increase-the polishing pressure.- Since-the lower platenf29 in both' ntlie, above circumstances would previously. have been. brought, into fixed contact with the glass ribbon by motor36, the application of thrust or polishingpressure on'the .top platen 17 will pinch or'fpress the glass'l0 between thefelt face .18 of I i I s .the "upper platen 17; and the. felt face, 30 of; the lower 19 includes a bell'crank or eccentric 20 mounted toplaten platen 29. Atthis time the platenstlfl,'29 wouldfbe in surfacing position and by proper regulation of the presin bearings 26a, it alsois-fixedly positionedwith respect vto the casing25' by collars ,26 and casing 25f is therefore vertically movable with shaft 21. This casing;25 is connectedby lug 27a to suitablernechanical lifting'gea'ring ,27, andto motor ZS sO -thatcasing 25 may be "mechani cally raisediandlowered away from the glass ribbon It),

thus raising and; lowering platen 17';

are likewise used to drive the lower platen or runner in? 16, similar components 5o dicated generally at 29 whicl1 has a 'felt face 39. A crank arrangement '31, similar to the'arran-gement 19 abovegat each end of platen 29 is'connected to'i each" shaft 32. Each shaft'32 bygearing 33, and,shafts{34is connected to afmotor 35' whereby a curvilinear transla ,tion movement is imparted to platen 29; Likewise,motor 36 through shafts 37, gearing 38 and further shafts39 are'connected to'the casing 40, through which the shafts I 32 passes and within which it'is vheld for free rotation so thatthe lower platen 29'n1ay also be lowered-away .and outrof engagement from the glass ribbon ltior moved upwardly in order to engage the ribbon 10L Since ithe 1 i detailed structure of the 'drivemechanisrn forms only an ancillary portion 'of this invention, only that structure deemed essential for ,an understanding of the basic fea-" tures of the operation of the platens or runners 17' and 29 has beenlshown and desc'ribed.

Connected 'tothe casing 25 ofnthe upperis'urfacing apparatus "15 is a fluid pressure sys em, the specific one?" illustrated being ,a hydraulic pressure system including by operation of motors 28 and 36.

sure'in the; hydraulic system 41 and 42, it wouldbe possible to place andmaintain the proper jsurfacing' pressure 7 ,upon the'glassribbonand therebyto properly surface the glass ribbon ltl whichtpasses between the: surfacing felts 18, and '30. The hydraulicsystem.41 and 42 thereforeapplies the positive load pressure which is used to surface the glass andthe load pressure'is-applied fatter ithe' tools or platens have been placed in engagement with the glass As aforediscussed, iti xtremely worki'rigface of the' surfacing platen. .In orderto accomplisli this "andalso to insure maximum surfacing work, ,thereihasbleen provided the improved platen or. runner This lplaten'lTis composed of a plurality of independent sections '56, the'actual number and dimensions .of which depend to a great extent upon the! particular surfacing requirements. I Since each-section 56 is identical,

it is believed that a detailed discussion of one section'56 will suffice asfa-descriptionof each and vevery section.

The felt surfacing portion 1810f each platen section 56 is adhered by an'adhesive or other suitable means to the undersurface of apressujre plate 57. Preferably,'disposed between the pressure plate -57-and the backing plate 58 of theirunner is a resilient, hollow and air-tight diaphragm 59'thatislboth expandable and retractable as will later -be discussed; a V a Each section of the pl ateni1 7 is heldiforjvertical slid'able-movemen't, i.e. perpfindicularly with respect to the plane of the glassribbon 10, 'by' suitable platen ribs surfacing tool 17 positively against ribbon '10: "It is 'believed that the description of one of these "devices will serve the purpose of describing both inasmuch as both 69 and; sidewalls 61 extending downwardly from the backing plate 58 inspace'dgsubstantially parallel relationship., l A'sseen in FIG. 3 the plate 570i each section 56is free to move vertically between adjacent ribs 60 and each side wall 61 and its adjacent rib while constrained .by these ribs 60 and sidewalls 61 against'lateral displacement. Also; asseen in FIG.Y.4, the platen 17 includes a pair of end walls ola'which holdtheplaten sections 56 against anylongitudinal shifting. Thus, the hollow inp I, a to maintain a proper distribution of .the surfacing. medium beneath the I medium feed means indicated generally at 77.

terior or compartment 62 is held substantially air tight by 'the friction fit between ribs 60, side walls 61 and end walls 61a with plate 57, or such air tightness may be further assured by provision of the diaphragm 59. The plate, however, is as above noted slidable between these ribs, side walls and end walls.

As illustrated in FIG. 3, the felt Working face 18 of each runner section 56 has a groove 63 cut therein which runs substantially transverse of the direction of glass movement and longitudinally of the runner 17. As shown in FIG. 4, these grooves or slots 63 are open at both ends of the runner 17, thus forming a continuous open passageway through the runner face 18 transversely across the surface of the glass. It is also pointed out that a further opening 63a is provided beneath the ribs 60 separating adjacent sections 56. The purpose of these openings 6311 will become apparent as theIdescription proceeds.

Turning again to FIG. 3, there is provided control means, indicated generally at 64, by which each of the separate sections 56 are selectively and individually raised" so as to be disengaged from the surface of glass ribbonll) are, predetermined or preselected moment. These control means 64 include a double acting pump 65 connected by a conduit system 66 to a suitable source of ,air 67. The pump 65 is also connected by means of a flexible conduit 68 to the hollow interior 62 of the diaphragm 5920f its respective section 56 of the platen 17. A timer 69 is also provided for each pump 65. to cause it to either introduce air under pressure to the interior 62 of the diaphragm 59 or tocausethe evacuation of air from the diaphragm 59. This pump 65. as shown is activated electrically. The pump 65 is connected by a suitable lead 71 to one of the main power lines 72, 73. Each individual timer 69 is connected by leads 74, 75 to the same linesource 72, 73 of power and connected by lead 76 to its respective pump 65 so that all of the timers of all pressure control means 64 may be electrically syn,- -chronized. 1 7 Also, as shown in FIG.- 3, the groove 63 in the working face 18 of each section 56 is connected to the polishing These means 77 include a flexible conduit 78 connecting groove 63 toa pump 79. This pump 79 is, by a conduit system 80, connected to a source 81 of the polishing medium. The operation of the pump 79 is. controlled by a suitable timer 82. The timer 32 and pump 79 for the slurry distribution means 77 for each section 56 are connected to each other by a lead 83, and by leads 84, 85 and 86 to the main power lines 72 and 73. Thus, timers 82 and 69 for all of the, polishing medium feed means 77 and all of the pressure control means 64, respectively, may be electrically synchronized one to each other.

In operation, and in order to maintain a constant supvply .ofpolishing medium under the working face 18 of each platen section 56, a fluid polishing medium is periodically fed interiorly of each individual section 56 and ,fed section is substantially simultaneously raised a small predetermined distance off the ribbon, e.g. 0.1 inch to 0.5

; inch. In this respect, the polishing medium is introduced fromconduit 78 under pressure into the interior of the section and through the groove 63 into contact with that portion of the glass ribbon immediately thereunder.

I The raising of a section 56 is accomplished by activating pump 65 of the pressure control means 64 by timer 69 so as to create a vacuum within the interior 62 of the diaphragm 59 of the platen section being fed. In this 'manner, with the activation of pump 79 of the polishing of the hollow diaphragm will force the plate 57 to rise upwardly and lift the felt working face 18 off the glass, as above noted. The polishing medium will then flow outwardly from the groove 63 across the surface of glass ribbon 10 and under the felt working face 18 of that section.

After feeding is completed, the timer 69 of the pressure control means 64 automatically activate pump 65 and forces air into the diaphragm 59 and causes the felt working face 18 to be thrust downwardly against the surface of the glass. Simultaneously, the timer 82 of the fluid medium distribution means 77 tie-activates its pumpr79 to discontinue the introduction of the fluid medium through the conduit 78 into groove 63. Any polishing medium remaining trapped in the grooves 63 upon reengagement of the working face 18 with the glass surface will tend to further saturate and impregnate the felt by absorption thereby.

It might be well here to point-out that the pressure exerted by pump 65 upon plate 57 through the diaphragm 59 is carefully controlled as against the hydraulic pressure or load pressure induced by the aforedescribed hydraulic system 41 and 42. This hydraulic system 41 and 42 determines the total bearing pressure for the runner as a unit and the individual pressure of each diaphragm 59 is maintained in balance with respect thereto during the polishing operation, i.e.,v a pressure is created therein through the pressure control means 64 except during the polishing fluid feeding step.

It is, however, also possible to modify the overall bearing pressure induced by system 41 and 42 and exerted by the platen 17 throughout its total area of contact with the glass ribbon. Thus, if desired, it would be possible through control of the individual diaphragm pressures, to exert a greater load pressure on the glass at, for example, the section 56'at the center of the platen than along the edges thereof, or to establish any desired pressure pattern across the transverse extent of the glass ribbon 10 during the polishing operation. In other words, if the total load pressure established by the hydraulic load system 41 and 42 was to be 3 p.s.i., the pressure at each individual section 56 through the use of the selective diaphragm pumps could be the same as, greater than, or less than 3 p.s.i.

This is important since, under certain conditions, it has been found desirable to vary the pressures of each section 56 as compared to the generally established pressure of the hydraulic load system 41 and 42, particularly since the felts themselves wear slightly during surfacing and may, under some circumstances, wear unevenly.

Thus, by the individual pressure control means 64 for each section 56 aforediscussed, greater flexibility is achieved by providing a means whereby it is possible to overcome runner wear for individual sections of the runner and to simultaneously either balance or unbalance, as desired, the load pressure of each section 56 on the surface of, glass ribbon 10.

By suitable synchronizing of timers 69 and 82 and pumps 65 and 79 of each section 56 with respect to all other sections, it is possible to feed and raise the sections one at a time, or two at a time, as desired, and also to raise them in sequential order or to vary the pattern, de-

pending upon the surfacing conditions desired.

Another modification of this concept is shown in FIG. 5, wherein the resilient diaphragms have been replaced by tension springs 88. These springs 88 normally tend to lift the plate 57 upwardly. However, this tendency is counterbalanced by the constant application of fluid, e.g. air, from a pump through conduit 68 leading into the chamber 62a whereby a pressure is maintained against the pressure plate 57 to hold the felt 18 against the glass. It is believed clear that in this modification, when this fluid application through conduit 68 is discontinued, the springs 88 will automatically raise the felt 18 off the glass. Thus, in this modification, a mechanical apparatus polished. a

for raising eachsection 56 is providedflrather than def through conduit 78"to raise the felt; The polishing medium pump associated with conduit 78 then is activated V changes in the shape,- size pending upon the pressure ofv the polishing medium" only for the purpose of feeding the medium and'can do a 5 so at amuch reduced pressure, 7

Turning now to l-TIG..6, Ttl1'issam'e'apparatus. as dethe lower platen or runner 29' separated by 'ribs' 60 in the same manner as above described for upperplaten 17. The significant difference between the upper and lower pressure control means is that, because of the weight of polishing medium, this air "under pressureifed through flexible conduit 95 need only be interrupted and the weight of the plate 94 will cause thesection 89' to: faIlHd Wnscribed above (FIGS. 3:and .4) is shown operating upon 8 and arrangement of parts,'.as well as, various procedural changes maybe resorted to withoutrdeparting'sfrom the spirit of the invention. 'Iclaimn r 1; In a method of polishing a surface'of a continuous glass ribbon moving relative to a surfacing tool, the working face' of said tool inclndinga surfacing runner having a plurality of; individually movable sections, the steps of pressing the surface runner into polish'ing engagement 'with said-glass ribbon surface, periodically feeding a fluid polishing medium interiorly of atfleastfone ofsaid sections, and substantially simultaneously with saidqfeeding disengaging any said/section being fed from the glass surface whereby said fluidpolishing rn'edium'comesinto adjacent any disengaged runner. section.

polishing {medium would be simultaneously and momenv tarily introduced unde'r'pressure frompiunp 96 ofa the lower platen feed means, indicated gene'rallyfatfl97,

through a flexible conduit 98 and sprayedfagainst the bottom surface of the glass ribbonjltltof-fiowacrossthe surface and 1 under those portions of .the-jglass opposite periodically feeding a fluid, polishing medium to each of the runner sectionsiin' timedrelationshipto each other.

' 13;"In a'method ofxsimultaneouslypolishing bot-h surfaces of a continuous glass ribbon movingbetweenat 7 least a pair of opposed surfacing tools, the working' 'face i ofveach tool including a su r'fac'ing runnerhaving a plu- Jrality' 'of' individually movable v'sectionsg'the steps of Ipressing the. surfacing runners into'polishing engagement withiboth surfacesof'the glass-ribbon,periodically feeda ing a fluid polishing medium"'interiorlyi of at least one 'of said sections, andsubstantiallyusimultaneously with a said feeding disengaging any said section being fed from to the felt working fac'e 30. It",willTbe' appreciated that J I v immediately adjacent fany disengaged runner section.

any of the'polishing medium fnot'a'dh'ering to the glass surface will fall backinto theYface3 0and serveto further impregnate thefelt'. Pumps 90@an d 9 6are-connectedby" suitable conduits 99 and 100 to air source 101- and-polishing medium source 102, respectively; 1 T he lower felts "Mare also grooved as atf103 'in amanner' similarjitof the grooves .63 of'the upper platen 17*. "A plurality of electricalleads 1Q4,;105;'and 106 connect the tirr'ierll07 of the lower platen pressure means to the. pump 90vandj to the line sourc'e of power 108, 109; The pum'p90gis also connected to the power line by lead1-10 Sirhila'r leads 111; 112 jand113'connect the timer 114 to thejpower lines 108, I09 and to pump 96'of the lower platen polisha ing mediumfe'ed means. jPurnpJ96 is connected to the powe'rflineby lead 115.Thus; timers 107 and, 114 may be electrically synchronized with respect-to each other '7 and also 'to the other pumpsa'nd timers of adjacent polishing fluid pressure means 97 and pressure control means9l.

Itwill be appreciated that' while thew orking face "or rubbing layer 'offthe platens 17 and'29 have'beengde scribed as being composed of; felt,'other resilien't'mater ials of'a difle'r'ent'fibrous composition; rubber or a; soft plastic,

could also be=satisfactorilyj employed.- ]It is a basic' requirement only that the materials used have the necessary combinationofrigidity'and flexibility so th'at they can 7 follow minute irregularities int the glass surface being .j 9

It should further be noted has been described and illustrated in cemeaonawim a twin grinding process; the novel' 'runners:and niethodof distributing a polishing medium as"disclo'sedherein rnay that; although the inventioh also be employed to advantage ina single surraeep nsh- It'is to be understood thatthe forms of the'i vention aerewim shown and described are to be taken as illu strm tive embodiments only ofthe same,"and'that yarious V the glass surface whereby? said fluid polishing medium comes intofcontact with thatlportiony'of the glass ribbon j .periodically'feeding 'a'fluidpolishing'mediumv 'to each of the runner. sections in timed relationship to each other.

f i I 5 g m iame'thodfof polishing a 7 surface of a continuous f glajss'fribbon;.movingf frelativelto 'agsurfacing -tool, the working face 'ofgsa'id tool including a surfacing ru'n'ner reiitendingi'generally, transverse of thejdirec'tionof movement of.said ribbon and having a=plurality of individually iver tic'ally-movable sections off-set from'each other in the'directions-of the. movement of said ribbon; -the" steps- I of) exerting a force [on said surfacing runner throughout .its total area I to' press said runner as a unit into polishing engagementswith vsaid glass ribbon Isurface', adjusting thepressure 'exerted .by; the runner o n the ribbon surface (along the direction} of movement of the ribbon by, individually controlling the force exertedthereon by each of 1 said runner sections, periodically feedingta', fluid polishing medium interio'rly' of at leastlone of/said sections, and substantially simultaneously with said feeding disengaging any said' section being fed ifr'om the: glass surface whereby said-fluid polishing medium comesinto contact jacent anydisengaged runner section;

i with that; portionofsthe glass" ribbon immediately ad- I References Cited b y theExam iner f V 1 V un rED i i r PA ES t 2,780,038

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contact with that portion'of the; glass ribbon immediately 

1. IN A METHOD OF POLISHING A SURFACE OF A CONTINUOUS GLASS RIBBON MOVING RELATIVE TO A SURFACING TOOL, THE WORKING FACE OF SAID TOOL INCLUDING A SURFACING RUNNER HAVING A PLURALITY OF INDIVIDUALLY MOVABLE SECTIONS, THE STEPS OF PRESSING THE SURFACE RUNNER INTO POLISHING ENGAGEMENT WITH SAID GLASS RIBBON SURFACE, PERIODICALLY FEEDING A FLUID POLISHING MEDIUM INTERIORLY OF AT LEAST ONE OF SAID SECTIONS, AND SUBSTANTIALLY SIMULTANEOUSLY WITH SAID FEEDING DISENGAGING ANY SAID SECTION BEING FED FROM THE GLASS SURFACE WHEREBY SAID FLUID POLISHING MEDIUM COMES INTO CONTACT WITH THAT PORTION OF THE GLASS RIBBN IMMEDIATELY ADJACENT ANY DISENGAGED RUNNER SECTION. 